SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '114ac404e458adcfad0966bdff291be1521e2f4ced31cd0f10550fa376434c4a' 
  AND token = 'X/eg0pH4x0gMyoJHh2CRWInYxMn9aUtdUywmJ2JNgkI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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