SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a98e0315c6be82d8fbb098ea0b11ffb73cda5a59a1c51fda67900412586513ac' 
  AND token = 'qVX8k7VqF3RHKEvP4ODbhlkUpECJ7OetB4YjMK+nqU0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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