SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '371519987ef3e69a07d95aed64bc346f7be70a9044f052b386939995d6d7c1a0' 
  AND token = 'B0ZCaD+ZvAISYanfvwb5bJoocaFCTWS0mgxZ0mzuuss=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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