SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4978e67ebf4f40370417193bf84e3c2d65cbafeef926c94dee710c0aaf148736' 
  AND token = 'fal4lXbQDEmUlWaBadquWu3p1/E4Wc8TYfBLzEPy18o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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