SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32291c131914b13ce5e68516ea86fcb8a7bb854ac20aa3f444fafb6bd289c251' 
  AND token = 'VRpow+YbJ0eVBAqD4Bmjvsbei9va8UnfXxH2BnLEIho=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}