SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0e344c001c5ccd703ffaded13664fad2d0619c11004209ef16e1bb67385e7e28' 
  AND token = 'OmZ7ZcQWWZvyQtwgO6HV7ZXP5XSkXnvFgL+yALjcBvg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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