SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52f2b10429866fe422003ae99346a4ec2df4868bda72361ea159a57f07507771' 
  AND token = 'oyz8bjtobQRlTjsCL7GrwNhHZlv/fQDC9jP4EXzqgk8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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