SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '78371ac5f41d84dd3dbcace83fdee780a54832c4e027c8623e0a034c6ae90133' 
  AND token = 'gMRhjPZhrMpwRG36o7JfnRGENrg2OvwV7LtpOVzVXiM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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