SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0449275a2c070f3331a75c2379339a8697c7141e12aeecfd1351f3e05755d07' 
  AND token = 'JQ84CdH+B3DXs9rlDwaY0cLJvMuitYFpcM7nPbLVQ5g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00115

JSON explain

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