SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '122b5e0b54ebaefcb7698b74a1adcf7908a7f56efe3d65061ce83d3113f88182' 
  AND token = '9sW6xzyZlWjV1Khy3KCvRp/UgHw8cchOMmjlT/Dhx94=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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