SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbfd3ef48cc89a399844e116267f9b7061d46eb232a94758a6bbd5febd147ba6' 
  AND token = '/4bSC4XfaEFzxarahUlFT/9hKdprSt3rjRQOF3Djvxo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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