SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c3966d864baef64bfe81a01c81973b167287ee0c3072fda643e6bfe0a7e5238' 
  AND token = '5X9t/M2WnwyfhqVbqTuxwxre+7wp+nz+ouzKYtgPTnQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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