SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '37ced9f98375841e59409b7cff05e9b2f647abdcd1b1f6def90b1d087362bfa3' 
  AND token = 'YjNG1MS+joVyu5R6soYOvqT1dLJm/ZFlWjsDChTpGgE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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