SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2bc84f6d84158dca571af99d28b9076ac31872949f956a6ad9e0343c14f1a173' 
  AND token = '7zvVJBrbcLO8Kn8uQSeZQC7k+I+ToV+ub5uBHTsTkAY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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