SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '84a7f2768aa2e8a993b50dba8f8e736d988d4b2f3a82564c05c73f3eb57f15bd' 
  AND token = 'T8mwGGTk+CMkX84bg5i6BmN45CwSq4RQ+4RiTl92APo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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