SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d29c38ffc57aa459edebba3347441a09b5afd705b0f9bfa789e620590ccefa2' 
  AND token = 'fZ4ZSdqrkH2vBupHEkNao0xi9K+FeochT+8Omf3E+Ms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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