SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b2eeb405875169678841b735bb798a1bee106832f03949a2b09c02d408389102' 
  AND token = 'X1NjjRm1MOdFghh4rFF4pz6LixKzg6mGYlYqUNV7TDo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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