SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bd7303aa61af28a813e9f550177ba0b6b1e73264bff0f66315f142490066a045' 
  AND token = 'mYTpP+Idi+/Nsw3oQTnnW3nbYNHawuGooU/uEOwAfpc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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