SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20f334fa5bfee778bf16bbe3f0fd5202e1ff0bc329e2b8864871025bd6fe392e' 
  AND token = 'vP8HsDHKl34i9VDp+IVb66Qa2ZUXZVgIbs+ibzrvgJc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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