SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f83738f2f9a2e6a1be62478db59bba77e6421188a0d786902428d5c84f9158d' 
  AND token = 'wcYpy5NMAiJ6Imz73mfkDIBRNdXyD0+KTYztpsdTAv0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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