SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6986f8f905513cd361160fb56366f024c113178d04befd3027d01c2cb64d3c9c' 
  AND token = 'x5S3oI4ulsI18RnS1OcCZql2ndTQUDu43VukPLzLRR8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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