SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c7a42c9584909a14208eb09541390e1b074b2bec150dbb5c6d98786149e69f94' 
  AND token = 'ME2hkQVhuvaIRC8DW4AnTzjQGI+eBRk7ZTq3LQwADEw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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