SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3880e235875cd57c8cf25adab52809754de6e7e822c3884cb42c98986fe6ab0' 
  AND token = 'R/FeRbryKFBHfON6w6zii5ZjaL4S9gg4KjHxgLAhP5Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00064

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}