SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7c3499f68a34ab82595cf1e4d1d3b16c50450f93a11c8c786ad0386079e3923a' 
  AND token = '/lsO8VyQpBcXtMC2nurD0X+FA4tE5LNM7fLnGAsx/pw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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