SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c7854558824491aedc09da89f378adb4b5fdd322c4fcbc663eba4bd55d9e008' 
  AND token = 'ASj9tRyRvD0Ql6XpSunMxyxuMNbvVfKquPwjGHXsJ2I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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