SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e353042d74c3562d278fe6f978a91b5a168a8564eb3143ea97e1fbab292669f0' 
  AND token = 'PNUHjjPhXZLN/56mCQ1KxenBXQQJOJnB+maOcqk+hgc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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