SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9de227d532125b109a9ef0c01ddd9550f188c71d16a8976368f87122c2147573' 
  AND token = 'Dbq974h0eFWDSnIM//jhmlMMJ/h0gH0/mCKi/oYJvPE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}