SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f3784452ffc9f135a523acfa82a168e8fd8f5e8b66334c1ddd9ba27d628db66' 
  AND token = 'cpqusZlwPQuaKl+1LeuIez3UrwAkcWOeF39AD+xhh4g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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