SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd9a3a7d50e2f7db4fb1f024f31d04d2f91e5aff9a6c6de735685fc9bd0e0b500' 
  AND token = 'BOZRXoNV+L7j776xS2mDd4ShZFEsGalP49qi1R91bBY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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