SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d3790c017d166cd96e6f5581c508a0e1d828caecc85cd0207f5496bcc7af61e' 
  AND token = 'oRXgpp0VK55BbI69jA1xtRBXazjnsa8KwH2t7YxtGYg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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