SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e28813ab792f9f5c0f4e74ef2aa70e13577b2c94da1a955428f9ead10339e8dd' 
  AND token = 'yfu7OFGuuAvCmio54h1bZRL9u/YahrWltsXquDNVJAA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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