SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb649f6dd888180b432abdb15a22499775fe43a0ec5005731e2b4282a1dec04b' 
  AND token = 'vyrYkxFejpNRVaLrehD6o/sHlA8DKljmP6p7tA9Q23w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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