SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63117f1f3ebf84814c2422016ef29403d40ce18b5710b43a33a7299d1926e4ce' 
  AND token = 'JTFlcKymTq3zvtRs1h9YnnFCYkwJM2cOlIKdkciQqjI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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