SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d7d608981df4525fbdb579b00b3a1b50a92f0d4c2d8d51fac9b3109a48c7fef' 
  AND token = 'iYv6lQH4REs92pLKZW5/uFdwENpIlQbFvmw76FjqPsc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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