SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bac9fb9a6c2306421d72b8917cd96e7518c77634bbb7359b5ebe17acad03c9e7' 
  AND token = 'i8Sr+rrFY0XV0uy72JoQuDiUDJdbKMOi9EpF/q2NrsQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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