SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97375d3105c4e2ee7431e35fe02efe2e8d5a821ac8cb02b317f5182973696f0a' 
  AND token = 'I9D1QRSWUPIZWbedVK9EBpbR0n4rXxNzFi+vkWTyMt4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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