SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8435cd15da3f367923c6dd69af6c88469e49cd1bd397d0312d907c4b4585e504' 
  AND token = 'oFX8ciZ7+zEtaHbbhn3d3jVfqpwC6X4+LUcsA708z8w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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