SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd792a17ca81b490fa72fad8c7d361640eca8734e599d46bd8b215cd2b191852' 
  AND token = 'gWVakS3gqEo29T4Q4UEJ6Om/pE2WuLfzGkFPHFPqjZg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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