SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '197a296635551234d62e9fc9d2bed182157ca6e81d5f7b8c87e30602492f5bcf' 
  AND token = 'iZssvs/dhJ9j0D0p0K6wTQ5dR/a7yXBM3wQQ3wEm4go=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00011

JSON explain

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