SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1f3b90291f0df4c2e6bcd181c256f4894d91cf246199ccc3499256d0d05cdced' 
  AND token = 'NZ0vBaQo5E1Q2qbvFpuLt1wwN7uP+3XgsrgBFTDGkh4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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