SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e27b77d7ca63ff2b70ea9d31729e8dc60809a506159dcfa5d700cdb39c0748c4' 
  AND token = '8DBxf9U5HXUv3LUQHdiPo3DYzhlrVqjG/n5g5MkHj5o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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