SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2264b14709131ade20afe4e17b736febcd2e3c791843c909bc8965568bf9720' 
  AND token = 'VP7CQkI6IUkrmMXdfWVjCY8Nl7npB5OK2R4GVYTYGqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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