SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ebf8021410477b59257c7e0b41c2f4a4826a800d0d61bf3c776ed65b7f733eca' 
  AND token = 'yx7psSzAE5TP7MDAkWd60aaKPLk2raEricoFcvKymts=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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