SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7d64c434fac02db5abe443fb94298e04e2a4cb2d6a92578abdcc6859d3b55013' 
  AND token = 'REVieGqN0JODWFGGOm2BalFLPF5jp9Wpka7+PEVPPhw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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