SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c9867ca29c8b31f3c3f4bd34b5995e2bebb7cd738a2b349d1522fcfe2c323e7a' 
  AND token = 'kRsQY3lQaDFXcnANpBvbHDUCjxigym3cMgL71Clw5ks=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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