SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c152dfa0ae1f8a92569766349225370549d5dd58281fc830bace039eb6b6641' 
  AND token = 'Lgq/Dpmbvdf/t0VmDdZV+JXMDvak8HGAuzhOVUnZZRk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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