SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '504357b42f8108475fbbaa059fcafd03d785cf489fa72d39e1f99aa25ba28efb' 
  AND token = 'a6eQlsSmlcu2p+k9xPb6HMI+a505sKfDc4Uc68qcbHg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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